The Audio Beat - Ypsilon Electronics Aelius Mono Amplifiers
16.06.2014
Equipment
Reviews
Print
Version
Ypsilon Electronics • Aelius Mono Amplifiers
It's "the sum total" that makes these mono amplifiers special.
by Marc Mick elson | March 12, 2012
psilon is the twentieth letter of the Greek alphabet and Aelius was a noted Greek scholar and orator, so it will
come as no surprise that the Ypsilon Aelius mono amps come from the cradle of Western civilization. These 200watt push-pull monoblocks are sophisticated hybrids, featuring a tube input stage using a single C3g -- a fairly
obscure metal-sleeve tube -- and a MOSFET output stage. They output 60 watts of their power in class A, which
means they'll run this way for the majority of listening, but perhaps even more significant is Ypsilon's claim that the
amps offer single-ended sonic purity and push-pull power. While this sounds immediately like marketing hyperbole,
Demetris Backlavas, the amp's university-trained design engineer, can back it up. He cites the Aelius's "balanced (or
you may call it bridged) single-ended output stage," for which both phases, plus and minus, carry signal. "The difficulty
of implementing this output stage," Backlavas went on, "is that it requires to be driven with a perfectly balanced signal.
And this was done with an interstage transformer, which took a long time and many trials to bring it to the level of
performance we wanted (-3dB@13Hz-70kHz)."
Price: $36,000 per pair.
Warranty: Three years parts and
labor.
Ypsilon Electronics
8 AG. Athanasioy St.
Peania - 19002
Athens, Greece
+30 210 66 44 588
www.ypsilonelectronics.com
Aaudio Imports
4871 Raintree Drive
Parker, CO 80134
(720) 851-2525
www.aaudioimports.com
What this means in non-engineering speak is that the Aelius's circuit is sort of a double hybrid: tube and solid state,
balanced and single ended -- with no feedback, an important design consideration for Backlavas. All of this makes for
an amplifier that is unlike any other produced today -- at least among the ones I'm aware of. Ypsilon itself is just as
unique. First, the company manufactures its own transformers. The cores are outsourced, but the design and winding
happens at the Ypsilon factory. Second, the solid-silver hook-up wire used in each Ypsilon product is proprietary, drawn
from bars of silver. A jeweler does this to Backlavas's specifications.
Connection to the Aelius is via RCA or XLR input, but counterintuitive perhaps to what I've divulged so far, only the
former is recommended for achieving the highest performance from the amps. The balanced input for the review amps
included a transformer not manufactured at Ypsilon, and this led to an obvious veiling -- with this "veiling" not being
part of the Aelius's sound through the single-ended input. It honestly did sound like something additional was in the
signal path, which was literally the case. Realizing this, Backlavas will be removing the transformer in future production
runs. For connection to the speakers, the amps use binding posts with frosted caps that look like they were made
specially for the frosted-silver Aelius.
One feature of the Aelius that I applaud loudly is its ground-lift switch, which could save you the time and
inconvenience of using cheater plugs if you have a ground-loop issue with your system. This is also an outward sign of
one of Backlavas's preoccupations: eliminating noise. He seems to have hit his mark. After initially installing the amps in
my system, connecting to the preamp and speakers, and turning everything on, I thought I had overlooked something,
because there was absolutely no background noise -- not even the omnipresent tube rush I had gotten used to
hearing. I put my ear up to the tweeter and heard complete silence. I hit play on the CD player, expecting nothing to
happen, and music poured forth. Luckily I didn't do something dumb like crank up the volume when I thought things
were amiss.
The amps definitely needed warm-up after turn on, sounding sterile when they were cold and then coming into
character after 30 minutes. However, they seemed so stable, so imperturbable, that I left them on almost indefinitely,
unless I knew I wouldn't be listening for days, the amps always being ready to make music.
The Aeliuses I reviewed were actually the second I pair received. The first arrived almost a year earlier, right after the
amps were introduced. I heard in them much of what the review amps achieved, along with a couple of aberrations that
were not befitting their pedigree and especially their cost. Most notable among these was a combination of thinness
and dryness in the mids that leaned out voices, making them sound more reproduced than real. Demetris Backlavas
evidently heard the same things, because a couple of months after I received the amps and completely out of the blue,
a revision was announced and the review amps were retrieved.
Lest conspiracy theorists think that I had something to do with this, I had zero contact with either Ypsilon or US
distributor Aaudio Imports, from whom I received the amps, while I did that initial listening. I was proceeding as usual
when, one day, the call came and the amps were picked up. As for why I didn't just write the review, what would have
been the point? That Aelius wasn't a product any longer.
However, as you may have noted, a third version of the Aelius is now on the way, although this time with unchanged
sonics (unless you listen balanced, that is). Thus, what I heard and describe, the product of listening single ended, will
mirror what you hear from a pair of Aelius monoblocks bought today.
The second time around
he sound of the Aelius monoblocks embodied seeming
http://www.theaudiobeat.com/equipment/ypsilon_aelius.htm
1/3
The Audio Beat - Ypsilon Electronics Aelius Mono Amplifiers
16.06.2014
opposites. On the one hand there was an
overwhelming clarity, which mixed supreme retrieval
of musical detail, transient definition, and front-and-center
tonal neutrality. On the other hand, there was an inherent
robustness and density that tracked from the highest
highs, through the mids and into the bass. Add in that
nonexistent noise floor and you have, I'm confident, one of
the most complete amps extant -- an amp whose personality was literally devoid of obvious weaknesses. This is not to
say that the Aelius did everything better than all other amps -- that beast has yet to be created. However, within a
broad level of performance, the Aelius competes with any amp I've heard -- and I suspect any amp made today.
Hearing familiar recordings was often an act of discovery, especially those whose sound is stellar in an absolute sense.
They could sound both fresh in specific ways and true to life generally. One recent and lucky addition to my collection
is the Mobile Fidelity version of Led Zeppelin II [Atlantic/Mobile Fidelity MFSL 1-065], the only one of Zeppelin's albums
reissued by MoFi (thus far -- we can always cross our fingers for the future). It has become the album I play for nonaudiophiles who want to either experience my system or hear the difference between digital and analog, and it never,
ever leaves them in anything short of complete awe. I paid a mere $35 for my near-mint copy -- more than its original
selling price, but $100 less than the going rate on eBay.
If you grew up in the 1970s or 1980s listening to FM rock radio, you know side two -- beginning with "Ramble On" and
closing with "Bring It On Home" -- by heart. It was a new experience with the Aelius monoblocks. The guitars had more
pummeling bite and the bass and drums were better defined and weightier. On side one, the ping-pong stereo effects of
"Heartbreaker" whizzed between the speakers with dizzying suddenness. No matter its version, this LP will never be a
test of dynamic range, as the music commences at loud and proceeds to louder still, but that's part of its relentless
charm. As much as the Mobile Fidelity remastering, I'm convinced, the Aelius monoblocks made this blues-rock warhorse sound exhilarating.
An amp that can do that is a rare thing -- if and only if it doesn't skew the spectral balance by goosing a particular
region or adding some amusical artifact that can enliven in the short term but wear thin over time. About the most that
can be said about the Aelius monoblocks in this regard is that their perspective is more forward of midhall, giving them
an insistence that imparts an agreeable vividness to the music. This is easier to appreciate at lower listening levels,
where you won't have to aurally squint to discern microdynamic contrasts, than higher ones, but the amps' inherent
grainlessness never made it an issue. When Miles Davis pulls out his mute, forwardness and especially treble grain have
nowhere to hide. While Someday My Prince Will Come is not Miles at his vital best, it's still has some lovely playing,
including John Coltrane's final work for the leader's first quintet. I have both the 45rpm LP [Columbia/Analogue
Productions APJ 8456-45] and SACD [Columbia/Analogue Productions CAPJ 8456 SA] and, as with Led Zeppelin II, the
music was rendered with such excitement with the Aeliuses that I began to reevaluate the playing. The digital version
didn't have quite the same lateral spread and the treble was a little less liquid -- both of which the Aelius amps
revealed.
Roy Gregory likes to talk about how great components actually make orchestras, ensembles and bands sound like they
play better -- more true to the music and their own intentions. This idea popped into my head as I listened to Someday
My Prince Will Come with the Ypsilon monos in the system -- the sound being infinitely well resolved for sure, but the
playing also being tighter and (for lack of a better way to express it) more effervescent. This was also apparent with
the 45rpm version of Seven Steps to Heaven [Columbia/Analogue Productions APJ 8851-45] -- the second incarnation
of Miles' quintet and a much more formidable session. This is what great audio gear should do: make the work of great
musicians sound greater still.
While the Aeliuses may have a tube in their signal path, there was
nothing classically tubey about their sound -- no cloying midrange,
no bass bloom at the expense of speed and slam. Perceived linearity
ruled, the mids having a meatiness that, once again, is rare for an
amp that's as tonally evenhanded as the Aelius. The bass was taut
and muscular, more deep than bloomy and warm, and it possessed
real power, especially with kick drum like that on Keith Richards' Main
Offender [Virgin V2-86499]. The realism quotient of this recording is
something to behold, the Ypsilon amps conveying not just the pop
and sock of the drum kit but also the sharp barrage of the electric
guitars. In fact, if you've heard this CD (it's also available on vinyl, but expect to pay dearly for it), you have a sense
of the personality of the Aeliuses: a slightly forward perspective, vividness throughout the music's entire range, fleet
transients that decay into blackness, roaring power.
And copious air throughout the soundstage. Darker-sounding amps can cramp things, conveying the presence of the
musicians better than a well-rendered sense of the space in which they perform. While the Ypsilon amps leaned to the
latter, they weren't devoid of warmth and dimensionality. At the recommendation of Richard Gerberg, the US ProAc
distributor, I've been listening to a lot Sun Kil Moon, the moniker of Mark Kozelek, founder of the Red House Painters.
His music and voice are reminiscent of Harvest-era Neil Young, and both bordered on luscious with the Aeliuses, which
neither turned his singing into sugary mush nor emphasized the nasal quality that gives it character.
The presentation was both truthful and beautiful, and this is what the best components achieve -- a balance in
portions so nearly ideal that any deviations are trifles in light of the totality of their performance. This is the Ypsilon
Aelius in summary. While no amp will please everyone equally, the Aelius has a better chance of achieving this than any
amp I've heard to date.
Hybrid hoe-down
hile hybrid amps like the Ypsilon Aelius make a great deal of sense, because they hold the promise of
combining tubes and solid state, there are surprisingly few of them. The dean of this select group is the
Lamm M1.2 Reference ($22,290), which, if you include its previous version, the M1.1 (and the MadisonFielding M1 before that), has been on the market for almost twenty years. Obviously, the core design of this amp has
great validity, both in terms of sonics and reliability: a tube input stage using a single 6922 followed by a MOSFET
output stage running in class A. There's much common ground with the Aelius here, although Vladimir Lamm has never
manufactured his own transformers or spec'd his own hookup wire, and the price of the M1.2s is less than two-thirds of
the price of the Ypsilon amps.
I've used the M1.2s as my reference for over five years. For reviewing, they offer great flexibility, as they have both
RCA and XLR inputs and there is no discernible sonic difference between them. They also have a switch on the back
that adjusts the idle current of the output stage, this depending on speaker impedance and ensuring that more of the
amp's output is in class A. Even without all of these niceties, the M1.2s would still be very high on my personal list of
amps because they sound glorious; I've often pointed out that they, along with other Lamm equipment, have as nearly
ideal a tonal balance as possible -- one that mimics the color, dimension and weight of real life. Absolute neutrality is a
thought construct; so many of the amps that are deemed "neutral" sound lean and tonally threadbare -- exactly what
the M1.2s do not.
From this you probably can guess that the Ypsilon and Lamm amps do not sound like the near relatives that they are.
While it's possible to discern the tube and transistor sides of each amp's personality, the Lamm amps take on more of
the traditional traits of tubes, displaying greater richness and warmth, a meatier and more expansive bottom end, and
sweeter treble than the Ypsilon amps. The Aeliuses have less of an overt tonal signature, though the density of their
mids might make you question this. They are faster into and out of each note, and their decay is more apparent, likely
due to their lower actual and perceived noise floor.
Main Offender illustrated the differences of the two amps well, the Lamms imparting greater heft to the Richards' lead
http://www.theaudiobeat.com/equipment/ypsilon_aelius.htm
2/3
The Audio Beat - Ypsilon Electronics Aelius Mono Amplifiers
16.06.2014
playing and that of the bassists, while the Ypsilons positively launched each drum strike into the room, portraying more
skin than the Lamm amps and, once again, conveying greater decay amidst a wide, deep soundstage.
Yet, these differences don't invalidate the notion that both amps offer a wide-ranging set of strengths and a
completeness of purpose. They prove once again the immutable law that similar design goals can lead to different sonic
outcomes. Such is the diversity of human nature -- and the variety of sounds that can still be deemed hi-fi.
The promise of promise
ruly great amps, like their equals in other product categories, are complex sonic entities. Some distinguish
themselves by pushing ahead the performance in one area, while others build on a defined set of traits, shoving
them all to new heights. The Ypsilon Aeliuses fit into neither of these camps, and yet they are certainly "truly
great amps." With them, it is the sum total of everything they do -- all to a very high level -- that's distinguishing, and
that so much of what they achieve is rare among amplifiers no matter the price. I've heard amps that track the signal
with as much speed as the Aeliuses and amps that are as quiet as the Aeliuses, but not amps that possess these
qualities along with the same midrange dimension and the same bass power -- the same level of overall realism -- as
the Aeliuses, all in one package.
The Greeks have been responsible for advancements in engineering, transportation, mathematics, sport, cartography,
philosophy, literature -- the list goes on and on. Even more upscale in the Ypsilon lineup are the SET 100 Ultimate
monoblocks, which are as large as computer servers and cost as much luxury cars -- each. Until I hear for myself that
they fulfill their enormous promise, the Aelius monoblocks will more than ably represent the audio advancements of the
Greeks -- and Ypsilon.
Associated Equipment
Analog: TW-Acustic Raven AC turntable, Graham B-44 Phantom Series II and Tri-Planar Mk VII UII
tonearms, Dynavector XV-1s (stereo and mono) and Allnic Puritas cartridges, AudioQuest LeoPard and
Nordost Odin phono cables, Allnic Audio H-3000V and Audio Research Reference Phono 2 phono stages.
Digital: Audio Research Reference CD8 CD player, Ayre Acoustics DX-5 "A/V Engine."
Preamplifiers: Audio Research Reference Anniversary, Convergent Audio Technology SL1 Legend, Lamm
Industries LL1 Signature.
Power amplifiers: Atma-Sphere MA-2 Mk 3.1 and Lamm Industries M1.2 Reference monoblocks.
Loudspeakers: ProAc Response K6, Wilson Audio MAXX 3 and Sophia 3.
Interconnects: AudioQuest William E. Low Signature, Shunyata Research PowerSnake Series Anaconda and
Python.
Speaker cables: AudioQuest William E. Low Signature, Shunyata Research PowerSnake Series Anaconda
and Python.
Power conditioners: Essential Sound Products The Essence Reference, Shunyata Research Hydra Triton.
Power cords: Essential Sound Products The Essence Reference and MusicCord-Pro ES, Shunyata Research
CX-series (various).
Equipment rack and platforms: Silent Running Audio Craz² 8 equipment rack and Ohio Class XL Plus2
platforms (under Lamm M1.2 amps), Harmonic Resolution Systems M3 isolation bases.
© The Audio Beat • Nothing on this site may be reprinted or reused without permission.
http://www.theaudiobeat.com/equipment/ypsilon_aelius.htm
3/3